Topical composition, topical composition precursor, and methods for manufacturing and using

ABSTRACT

A tropical composition is provided. The topical composition can be prepared by diluting a topical composition precursor with water and adding additional components, if desired. The topical composition precursor can be prepared by melt processing a hydrophobic polymer composition that includes repeating pyrrolidone/alkylene groups wherein the alkylene groups contain at least 10 carbon atoms, and a hydrophilic polymer composition including repeating carboxylic groups and/or repeating hydroxyl groups. A topical composition precursor and methods for manufacturing and using a topical composition are provided by the invention.

FIELD OF THE INVENTION

[0001] The invention relates to a topical composition, a topicalcomposition precursor, and methods for manufacturing and using thetopical composition and the composition precursor.

BACKGROUND OF THE INVENTION

[0002] Naturally occurring and synthetic polymers have been used inpharmaceutical and cosmetic preparations for several decades. Polymersthat have been used in pharmaceutical and cosmetic preparations includehydrophilic polymers, hydrophobic polymers, and polymers havinghydrophilic and hydrophobic properties. Hydrophilic polymers are oftenused as thickeners and/or film formers. Hydrophobic polymers are oftenused because of their ability to hold active ingredients and to bind toskin.

[0003] Compositions have been developed for enhancing the cutaneouspenetration of topically or transdermally delivered pharmacologicallyactive agents. For example, see U.S. Pat. Nos. 5,045,317; 5,051,260; and4,971,800.

SUMMARY OF THE INVENTION

[0004] A topical composition, a topical composition precursor, andmethods for manufacturing and using a topical composition and a topicalcomposition precursor are provided by the invention. The topicalcomposition can be referred to as a “delivery system” when it is used topromote the delivery of active ingredients to skin tissue. When providedas a use solution, the topical composition has an ability to adhere orbind to skin tissue and thereby hold active ingredients in proximity toskin tissue. In addition, the topical composition has an ability to holdor contain active ingredients so that the active ingredients can be madeavailable to skin tissue when the topical composition is applied to skintissue. Active ingredients that can be used include natural andsynthetic substances that produce a desired effect when placed on skintissue and may include medicines or drugs or other substances intendedfor the diagnosis, cure, mitigation, treatment, or prevention of adisease or condition, and may include substances that may becharacterized as protectants, repellants, and moisturizers.

[0005] The topical composition precursor of the invention can beprovided as a result of melt processing a hydrophobic polymercomposition and a hydrophilic polymer composition in the presence ofless than about 1 wt. % water. The hydrophobic polymer compositionincludes a poly(vinylpyrrolidone/alkylene) polymer wherein the alkylenegroup contains at least about 10 carbon atoms. The hydrophilic polymercomposition includes at least one of a hydrophilic polymer comprisingrepeating carboxylic acid groups and/or repeating hydroxyl groups.Exemplary hydrophilic polymers include polyacrylic acid having a weightaverage molecular weight of at least about 50,000 and exhibiting lessthan 1% cross-linking, poly(maleic acid/methylvinylether) copolymerhaving a weight average molecular weight of at least about 50,000,starch, derivatives of starch, cellulose, derivatives of cellulose,carboxymethyl cellulose, polyvinyl alcohol, cyclodextrins, dextrans, andmixtures thereof. The hydrophilic polymer composition can includepolyacrylic acid having a weight average molecular weight of betweenabout 50,000 and about 4,000,000, and exhibits less than 1%cross-linking and/or poly(maleic acid/methylvinylether) copolymer havinga weight average molecular weight of between about 50,000 and about4,000,000.

[0006] The hydrophobic polymer composition can include a mixture ofdifferent poly(vinylpyrrolidone/alkylene) polymers. When the hydrophobicpolymer composition contains a mixture of two differentpoly(vinylpyrrolidone/alkylene) polymers, the firstpoly(vinylpyrrolidone/alkylene) polymer can be provided at aconcentration of between about 5 wt. % and about 54 wt. %, based on theweight of the hydrophobic polymer composition. In addition, the secondpoly(vinylpyrrolidone/alkylene) polymer can be provided at aconcentration of between about 46 wt. % and about 95 wt. %, based on theweight of the hydrophobic polymer composition. Exemplarypoly(vinylpyrrolidone/alkylene) polymers includepoly(vinylpyrrolidone/1-eicosene) polymer andpoly(vinylpyrrolidone/hexadecene).

[0007] The topical composition precursor can be formed by mixing thehydrophobic polymer composition and the hydrophilic polymer compositionin a melt and providing a functional group parity between thepyrrolidone groups of the hydrophobic polymer composition and thecombination of carboxylic acid groups and/or hydroxyl groups of thehydrophilic polymer composition that is between about 1:1 and about 5:1,and can be between about 1.5:1 and about 3:1. For certain compositions,it is expected that this functional group parity of the hydrophobicpolymer composition to the hydrophilic polymer composition will resultin a topical composition precursor containing about 72 wt. % to about 98wt. % hydrophobic polymer composition and about 2 wt. % to about 25 wt.% hydrophilic polymer composition, based on the total weight of thetopical composition precursor.

[0008] A topical composition is provided according to the invention. Thetopical composition can include the topical composition precursor andcan include a result of diluting the topical composition precursor withwater. The topical composition preferably includes a result of hydratingthe topical composition precursor with water to provide at least about30 wt. % water. The topical composition can be characterized as aconcentrate if it contains between about 30 wt. % and about 70 wt. %water based on the weight of the topical composition. It is expectedthat the concentrate will be provided with a water concentration ofbetween about 30 wt. % and about 45 wt. % to reduce costs associatedwith shipping water. When the topical composition is provided as a usesolution for application to skin tissue, it is expected that thecomposition will contain at least about 70 wt. % water and can includebetween about 70 wt. % and about 96 wt. % water, based on the weight ofthe topical composition.

[0009] The topical composition can include active ingredients such asantimicrobials, antifungals, anti-inflammatory agents, anti-viralagents, drugs, sunscreens, vitamins, alpha-hydroxy acids, surfactants,dyes, fragrances and pigments.

[0010] The topical composition can include a surfactant or a mixture ofsurfactants to enhance the stability of the topical composition and/orto enhance the rate of release of active ingredients. Exemplarysurfactants that can be used according to the invention include nonionicsurfactants, anionic surfactants, cationic surfactants, amphotericsurfactants, and mixtures thereof. Exemplary nonionic surfactants thatcan be used according to the invention include ethoxylated surfactants,propoxylated surfactants, and ethoxylated-propoxylated surfactants. Anexemplary ethoxylated surfactant includes nonylphenol ethoxylate havingabout nine ethylene oxide repeating groups. The surfactant component canbe incorporated into the topical composition in an amount sufficient toprovide the desired stability and the desirable rate of release ofactive ingredients. In most applications, it is expected that thesurfactant will be provided in an amount of up to about 5 wt. %, andwill more likely be provided in an amount of between about 0.5 wt. % andabout 5 wt. %.

[0011] A method for manufacturing a topical composition is providedaccording to the invention. The method includes a step of meltprocessing a mixture of a hydrophobic polymer composition and ahydrophilic polymer composition to provide a topical compositionprecursor, and diluting the topical composition precursor to provide aconcentrate having a water concentration of at least about 30 wt. %,based on the weight of the topical composition. The step of meltprocessing preferably includes mixing the hydrophobic polymercomposition and the hydrophilic polymer composition at a temperature ofgreater than 50° C., and more preferably greater than about 125° C. Thestep of melt processing preferably includes mixing the hydrophobicpolymer composition and the hydrophilic polymer composition at awater-concentration of less than about 1 wt. %.

[0012] A method for using a topical composition is provided according tothe invention. The method includes applying the topical composition toskin tissue.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a graph showing the change in percent free COOH ofmaleic acid/methylvinylether copolymer as a function of percentpolyvinylpyrrolidone with 1-eicosene;

[0014]FIG. 2 is a graph showing percent free COOH of MMVE as a functionof percent PVPH added;

[0015]FIG. 3 is a graph of percent titratable COOH groups of MMVE as afunction of percent PVPE or PVPH added;

[0016]FIG. 4 is a graph showing the effects of adding 20 to 50 wt. %PVPE or PVPH on pKa and equivalent weight of MMVE;

[0017]FIG. 5 is a graph showing MMVE solution viscosity as a function ofpercent PVPH or percent PVPE added and temperature;

[0018]FIG. 6 is a graph showing MMVE viscosity as a function oftemperature and percent of PVPH and PVPE;

[0019]FIG. 7 is a graph showing the percent of polymer remaining boundto hydrophilic nylon membranes as a function of increasing percentage ofPVPH or PVPE polymer;

[0020]FIG. 8 is a graph showing the percent of polymer remaining boundto hydrophilic nylon membranes as a function of increasing percentage ofPVPH+5 wt. % or 10 wt. % PVPE polymer;

[0021]FIG. 9 is a graph showing the percent of starch-polymer complexbound as a function of percent PVPH at 5 wt. %, 10 wt. %, and 54 wt. %PVPE;

[0022]FIG. 10 is a graph showing the percent of PVOH-polymer complexbound as a function of percent PVPH at 5 wt. %, 10 wt. %, and 54 wt. %PVPE;

[0023]FIG. 11 is a graph showing the percent of CM-cellulose-polymercomplex bound as a function of percent PVPH at 5 wt. %, 10 wt. %, and 54wt. % PVPE;

[0024]FIG. 12 is a graph showing the percent of cyclodextrin PVPH andPVPE polymer complex bound at 5 wt. %, 10 wt. %, and 54 wt. % PVPE;

[0025]FIG. 13 is a graph showing the percent of Dextran 70 polymercomplex bound as a function of percent PVPH at 5 wt. %, 10 wt. %, and 54wt. % PVPE;

[0026]FIG. 14 is a graph showing the pKa for MMVE/PVP polymer complex.

DETAILED DESCRIPTION OF THE INVENTION

[0027] A topical composition and a topical composition precursor areprovided by the invention. The topical composition precursor refers to arelatively anhydrous composition that is used to form the topicalcomposition use solution or working solution. The topical compositionuse solution or working solution refers to the composition intended tobe applied directly to skin tissue. It should be understood that thephrase “topical composition” refers to any composition that includes thetopical composition precursor as a component or that can be formed fromthe topical composition precursor, and may be provided in the form of aprecursor, a concentrate, a use solution, or an intermediate in theproduction of a topical composition use solution.

[0028] The topical composition can be referred to as a delivery systemwhen it includes an active ingredient for delivery to skin tissue. Thetopical composition according to the invention is advantageous becauseof its ability to bind or adhere to skin tissue for a length of time andbecause of its ability to hold or contain active ingredients within thecomposition to allow for delivery of the active ingredients to skintissue. It is expected that the topical composition is able to adhere orbind to skin tissue for at least about four hours and holds the activeingredients contained therein in proximity to skin tissue for thatlength of time to allow for delivery of the active ingredients to theskin tissue. In general, it is expected that the topical compositionwill bind or adhere to skin tissue for at least four hours even afterseveral applications of washing and scrubbing of the skin tissue. It isexpected that the natural exfoliation of the skin will cause the removalof most of the topical composition from the skin tissue.

[0029] The topical composition precursor can be prepared by meltprocessing a hydrophobic polymer composition and a hydrophilic polymercomposition to provide an interaction between the hydrophobic polymercomposition and the hydrophilic polymer composition. It should beunderstood that the phrase “melt processing” refers to mixing thehydrophobic polymer composition and the hydrophilic polymer compositionunder conditions that provide that the hydrophobic polymer component ofthe hydrophobic polymer composition and the hydrophilic polymercomponent of the hydrophilic polymer composition are in a liquid stateso that they sufficiently mix. When the polymers are sufficiently mixed,it is believed that an interaction forms between the hydrophobic polymercomponent and the hydrophilic polymer component. The melt processingtemperature is preferably at least about 50° C. and more preferably atleast about 125° C. to generate this interaction.

[0030] It is believed the interaction exhibited between the hydrophobicpolymer component and the hydrophilic polymer component is a type ofcomplex formation reaction, and that the complexes, once formed, arestable in water at temperatures up to 65° C. and at a pH range of 3.0 to9.0. By stable, it is meant that the complexes do not favordisassociation. It is believed that this interaction provides thetopical composition with an ability to bind or hold onto hydrophobicactive ingredients that are emulsified in water, and provides thetopical composition with an ability to bind to skin and/or substrates ofpredominantly hydrophobic character.

Hydrophobic Polymer Composition

[0031] The hydrophobic polymer composition that can be used according tothe invention includes repeating pyrrolidone/alkylene groups. Exemplarypolymers that have repeating pyrrolidone/alkylene groups includepoly(vinylpyrrolidone/alkylene) polymers.Poly(vinylpyrrolidone/alkylene) polymers include those polymers obtainedby a polymerizing alkylene substituted vinylpyrrolidone. The polymerscan be represented by the following general formula:

[0032] wherein R represents a carbon chain substitute such as analkylene group and n represents the number of repeating units. The Rgroup is preferably sufficiently long so that the polymer remainsrelatively water insoluble and should not be too long so that thepolymer is difficult to melt process. Preferably, the alkylene groupcontains a length of at least about 10 carbon atoms and contains no morethan about 25 carbon atoms. Preferably, the alkylene group containsbetween about 14 carbon atoms and about 22 carbon atoms, and morepreferably between about 15 carbon atoms and about 19 carbon atoms.

[0033] The poly(vinylpyrrolidone/alkylene) polymers that can be usedaccording to the invention preferably have a molecular weight that issufficiently high so that the polymer maintains its water insolubilitybut the molecular weight should not be so high that it becomes difficultto melt process the polymer. Preferably, the weight average molecularweight of the poly(vinylpyrrolidone/alkylene) polymer is between about3,000 and about 400,000. Another way to characterize the size of thepoly(vinylpyrrolidone/alkylene) polymer is by the number of repeatingunits (n). In the case of a poly(vinylpyrrolidone/alkylene) polymerhaving a weight average molecular weight of between about 6,000 andabout 30,000, the poly(vinylpyrrolidone/alkylene) polymer has betweenabout 20 and about 80 repeating units, and more preferably between about30 and about 50 repeating units. It should be understood that repeatingunits refer to the residues of vinylpyrrolidone/alkylene groups.

[0034] Preferred poly(vinylpyrrolidone/alkylene) polymers that can beused according to the invention includepoly(vinylpyrrolidone/1-eicosene) and poly(vinylpyrrolidone/hexadecene).Poly(vinylpyrrolidone/1-eicosene) can be referred to as PVPE and iscommonly used in pharmaceutical and cosmetic preparations. A preferredform of PVPE for use according to the invention includes about 43 to 44repeating units in length and has a weight average molecular weight ofabout 17,000 and can be characterized as a paraffin-like solid. Thisparticular PVPE is highly insoluble in water, and has an extremely loworal toxicity (LD₅₀>17000 mg/kg) and exhibits no demonstrable dermaltoxicity. Poly(vinylpyrrolidone/1-hexadecene) can be referred to asPVPH. A preferred form of PVPH is available as a viscous yellow liquidthat is insoluble in water and has a low oral toxicity (LD₅₀>64000mg/kg), has about 39 to 40 repeating units, a molecular weight of about1,400, and exhibits no demonstrable dermal toxicity.

[0035] PVPE and PVPH differ in the length of the hydrocarbon side chain,and are used extensively in the skin care industry, usually inconcentrations of less than 1% by weight, because of their ability tobind to skin. Because the skin care industry generally prefers to applyactives to skin using a water-based composition, the use of PVPE andPVPH often requires solvents, surfactants, and emulsifiers to stabilizethese polymers in a water emulsion. However, many of the solvents,surfactants and emulsifiers used to stabilize PVPE and PVPH in a wateremulsion lack the low dermal toxicities of PVPE and PVPH. PVPE and PVPHby themselves lack a cosmetically elegant appeal when applied directlyto the skin. They tend to be sticky and greasy.

[0036] The hydrophobic polymer composition used according to theinvention is preferably provided as a mixture of differentpoly(vinylpyrrolidone/alkylene) polymers. The mixtures of differentpoly(vinylpyrrolidone/alkylene) polymers preferably include at least 5wt. % of a first poly(vinylpyrrolidone/alkylene) polymer based on theweight of the hydrophobic polymer composition. The hydrophobic polymercomposition preferably includes between about 5 wt. % and about 54 wt. %of the first poly(vinylpyrrolidone/alkylene) polymer. The secondpoly(vinylpyrrolidone/alkylene) polymer is preferably provided in anamount of at least about 46 wt. % and preferably in a range of betweenabout 46 wt. % and 95 wt. %. For a hydrophobic polymer compositioncontaining a first poly(vinylpyrrolidone/alkylene) polymer and a secondpoly(vinylpyrrolidone/alkylene) polymer, the mole ratio of the firstpolymer to the second polymer is preferably between about 1:22 and about1:1. In general, when the hydrophobic polymer composition contains amixture of different poly(vinylpyrrolidone/alkylene) polymers, it ispreferable to provide at least one of thepoly(vinylpyrrolidone/alkylene) polymers in an amount that providesimproved properties to the topical composition compared to a topicalcomposition having a hydrophobic polymer composition containing a singlepoly(vinylpyrrolidone/alkylene) polymer.

[0037] When the hydrophobic polymer composition is provided as a mixtureof PVPH and PVPE, it is preferable that the PVPH is provided in therange of between about 46 wt. % to about 95 wt. % and the PVPE isprovided in the range of between about 5 wt. % and about 65 wt. %, basedupon the weight of the hydrophobic polymer composition.

Hydrophilic Polymer Composition

[0038] The hydrophilic polymer composition that can be used according tothe invention includes at least one hydrophilic polymer and may includea mixture of hydrophilic polymers. The hydrophilic polymers that can beused according to the invention include polymers having repeatingcarboxylic acid groups and/or hydroxyl groups. Preferred hydrophilicpolymers that can be used according to the invention include polyacrylicacid polymers and poly(maleic acid/methylvinylether) copolymers.

[0039] Polyacrylic acid polymers that can be used according to theinvention preferably have a weight average molecular weight of at leastabout 50,000, and more preferably between about 50,000 and about4,000,000. In addition, the polyacrylic acid polymers preferably have alevel of cross-linking that is less than about 1%. A general structuralrepresentation of polyacrylic acid polymers is shown below:

[0040] wherein n is the number of repeating units and is preferablybetween about 1,000 and about 20,000.

[0041] Poly(maleic acid/methylvinylether) copolymers that can be usedaccording to the invention preferably have a weight average molecularweight of at least about 50,000, and preferably between about 50,000 andabout 4,000,000. The weight average molecular weight is more preferablybetween about 70,000 and 2,500,000. A general structural representationof poly(maleic acid/methylvinylether) copolymers is shown below:

[0042] wherein n is the number of repeating units and is preferablybetween about 200 and about 20,000.

[0043] Additional hydrophilic polymers that can be used according to theinvention include starch, derivatives of starch, polyvinyl alcohol,cellulose, derivatives of cellulose, carboxymethyl cellulose,cyclodextrins, and dextrans. Exemplary starches include amylopectin andpolyglucose. The weight average molecular weight of the hydrophilicpolymers is preferably sufficient to provide solubility in water but nottoo high to become difficult to process. Starches that can be usedaccording to the invention preferably have a weight average molecularweight of between about 50,000 and about 20,000,000. A derivative ofstarch that can be used according to the invention includes partiallyhydrolized starch. Cellulose that can be used according to the inventionpreferably has a weight average molecular weight of between about 50,000and about 15,000,000. Polyglucose that can be used according to theinvention can be characterized as low fraction polyglucose having aweight average molecular weight of between about 60,000 and about90,000, and high fraction polyglucose having a weight average molecularweight of between about 90,000 and about 300,000. An exemplary lowfraction polyglucose material that can be used according to theinvention is available under the name Dextran-70. In general, this typeof polyglucose has all alpha 1-6 linkages. Starch derivatives that canbe used according to the invention include those starch derivativeshaving alpha 1-4 linkages. An example of this type of starch derivativeincludes cyclodextrins. Preferred cyclodextrins that can be usedaccording to the invention are those that act to provide a cavity withinthe molecule large enough to contain components desirable for topicalapplications. Preferably, the cyclodextrins that can be used accordingto the invention have a molecular weight of between about 900 and about1,400. Polyvinyl alcohols that can be used according to the inventionpreferably have a weight average molecular weight of between about50,000 and about 200,000.

[0044] Exemplary hydrophilic polymers that can be used according to theinvention include those polymers having the following meltingtemperature range and the following maximum temperature range beyondwhich it is expected decomposition of the polymer will occur. Exemplarypoly(maleic acid/methylvinylether) copolymers that can be used includethose having a melting temperature range of between about 60° C. andabout 65° C. and a maximum temperature range of between about 80° C. andabout 90° C. Exemplary polyacrylic acid polymers that can be usedinclude those having a melting temperature range of between about 65° C.and about 70° C. and a maximum temperature range of between about 80° C.and about 90° C. Exemplary carboxymethyl cellulose polymers that can beused include those having a melting temperature range of between about55° C. and about 60° C. and a maximum temperature range of between about75° C. and about 80° C. Exemplary polyvinyl alcohol polymers that can beused include those having a melting temperature range of between about50° C. and about 55° C. and a maximum temperature range of between about65° C. and about 70° C. Exemplary starches that can be used includethose having a melting temperature range of between about 40° C. andabout 45° C. and a maximum temperature range of between about 50° C. andabout 55° C. Exemplary dextrans that can be used include those having amelting temperature range of between about 37° C. and about 40° C. and amaximum temperature range of between about 45° C. and about 50° C.Exemplary β-cyclodextrins that can be used according to the inventioninclude those having a melting temperature range of between about 40° C.and about 45° C. and a maximum temperature range of between about 65° C.and about 70° C.

Processing

[0045] The hydrophobic polymer composition and the hydrophilic polymercomposition are preferably combined and heated to at least about 50° C.to provide a polymer melt. The composition is preferably heated to atleast about 125° C. under mixing to form complexes between thehydrophobic and hydrophilic polymers.

[0046] The complex formation step is preferably carried out in arelatively anhydrous environment. That is, the amount of water providedin the composition during the complex formation step is preferably lessthan about 1 wt. %. Once the desired level of complex formation hasoccurred, the composition can be hydrated with water.

[0047] The hydrophobic polymer composition and the hydrophilic polymercomposition are preferably mixed together in amounts sufficient toprovide a ratio of pyrrolidone groups to the combination of carboxylicacid groups and hydroxyl groups of between about 1:1 and about 5:1. Theratio of the structures causing the observed interaction between thehydrophobic polymer composition and the hydrophilic polymer compositioncan be referred to as “functional group parity.” Preferably, the ratioof pyrrolidone groups to the combination of carboxylic acid groups andhydroxyl groups is between about 1.5:1 and about 3:1. In order to drivethe complex formation reaction, it is desirable to provide an imbalancebetween the two types of groups. Accordingly, it is generally desirableto provide more of the pyrrolidone groups than the combination ofcarboxylic groups and the hydroxyl groups. It should be understood thatthe reference to a “combination of carboxylic groups and hydroxylgroups” refers to the total amount of carboxylic groups and hydroxylgroups present but does not require the presence of both carboxylicgroups and hydroxyl groups. For example, the value of the combination ofcarboxylic groups and hydroxyl groups can be determined for acomposition that contains only carboxylic groups. Similarly, the valuecan be determined for a composition that contains only hydroxyl groups.

[0048] During the complex formation step, the amounts of hydrophobicpolymer composition and hydrophilic polymer composition can becharacterized on a weight percent basis. Preferably, about 2 wt. % toabout 28 wt. % hydrophilic polymer composition and about 72 wt. % toabout 98 wt. % hydrophobic polymer composition are combined to providefor complex formation. Preferably, about 8 wt. % to about 25 wt. %hydrophilic polymer composition and about 72 wt. % to about 95 wt. %hydrophobic polymer composition are combined to form the complex. Duringthe complex formation step, the amount of water available in thecomposition is preferably less than about 1 wt. %. Although the complexforming composition can be relatively anhydrous, it is expected that theamount of water will be between about 0.3 wt. % and about 1.0 wt. %.

[0049] Once the hydrophobic polymers and the hydrophilic polymers havesufficiently reacted or interacted to form complexes, it is desirable toadd water to the composition to provide a stable aqueous compositionthat can be relatively easily further hydrated. The stable aqueouscomposition that can be easily diluted further with water to form theuse solution can be referred to as the concentrate. It is generallydesirable to hydrate the composition to a water content that provides arelatively stable composition and that allows for water to be added at alater date without much difficulty. Although water can be added to thecomposition to a level equivalent to the level of the topicalcomposition use solution, it is desirable to minimize the amount ofwater to avoid having to ship water. Shipping excess water is expectedto add cost to composition. In addition, it has been found that thefirst hydration of the topical composition precursor is the mostdifficult hydration step because of the need to control the conditionsof hydration. After the first hydration to a water content of at leastabout 30 wt. %, it is expected that further hydrations to higher watercontents are relatively easy and can be accomplished by simply mixingthe composition with water. Accordingly, the amount of water provided inthe composition when made available as a concentrate for shipment ispreferably between about 30 wt. % and about 45 wt. %. When thecomposition includes about 30 wt. % to about 45 wt. % water, it isexpected that the composition will include between about 3 wt. % andabout 10 wt. % hydrophilic polymer composition and between about 30 wt.% and about 50 wt. % hydrophobic polymer composition.

[0050] Water is added to the relatively anhydrous composition by mixingwater and the relatively anhydrous composition at a temperature and fora time sufficient to allow the composition to become hydrated withoutlosing significant amounts of interaction between the hydrophobicpolymer composition and the hydrophilic polymer composition. In general,the relatively anhydrous composition is hydrated by heating to at least60° C. and adding water while mixing. Preferably, the composition isheated to at least about 65° C. and more preferably at least about 70°C. A preferred temperature range is about 65° C. to about 80° C.

[0051] The relatively anhydrous composition can be referred to as thetopical composition precursor. The topical composition having a waterconcentration of between about 30 wt. % and about 95 wt. % can bereferred to as the concentrate. It is expected that the concentrate willbe made available to manufacturers of topical compositions. In addition,it is expected that the concentrate made available to manufacturers oftopical compositions will have a water concentration of between about 30wt. % and about 45 wt. %. The manufacturers of topical compositions willeither further hydrate the composition or use it as it is made availableto them. In most applications, it is expected that the topicalcomposition manufacturers will dilute the topical compositionconcentrate to the desired concentration of water and polymercomponents, and then use that composition as a component of the topicalcomposition.

Additional Components

[0052] The topical composition use solution is preferably prepared bymixing the topical composition concentrate with additional componentsfor the formation of the use solution. Components that can beincorporated into the composition for forming the use solution includethose components normally encountered in the topical compositionindustry. Exemplary components include antimicrobial agents, antifungalagents, anti-inflammatory agents, anti-viral agents, sunscreens,vitamins, α-hydroxy acids, surfactants, pigments, and dyes. Componentsthat are generally best suited for the composition of the inventioninclude those active ingredients that can be characterized ashydrophobic, neutral polar such as alcohols, and acidic.

[0053] Exemplary antimicrobial agents or biocidal agents that can beused according to the invention include those agents that are known tothose of skill in the art, including quaternary ammonium compounds andperoxygen compounds such as peroxy acids. Biocidal agents that can beused include chlorinated diphenyl ethers such as those available underthe tradename Triclosan®. When used, this agent can be present at aconcentration of about 0.9 to about 1.1 wt-%, more preferably about 1.0wt-%. Tricosan® gives a broad spectrum of pathogenic coverage and has along history of safe usage with a benign toxicological profile. Anexemplary natural antimicrobial agent that can be used for treatinginflammation and psoriasis includes silver.

[0054] Exemplary antifungal agents that can be used include sulconazole,naftifine, morpholines, allylamines, triazoles, clotrimazole andmiconazole nitrate.

[0055] The topical composition can also be used as long lasting carriersfor insecticides. A number of insecticides are known in the art as safefor human use, including citronella. Preferred insecticides includeN,N′-diethyl-3-methylbenzamide, commonly known as DEET.

[0056] Exemplary sunscreen agents that can be used include FSDA approvedmaterials such as aminobenzoic acid-PABA, cinoxate, diethanolaminemethoxycinnamate, digalloyl trioleate, dioxybenzone, ethyl4[bis(hydroxypropyl)] aminobenzoate, glyceryl aminobenzoate, homosalate,lawsone with dihydroxyacetone, mentyl anthranilate, octocrylene, octylmethoxycinnamate, octyl salicylate, oxybenzone, benzophenone, padimate,phenylbenzimidazole sulfonic acid, red petrolaum, sulisobenzone,titanium dioxide, trolamine salicylate, and combinations of the above.Preferred sunscreen materials include a mixture of octylmethoxycinnamate and benzophenone.

[0057] Exemplary active ingredients that can be used in the topicalcomposition include benzalkonium chloride (antimicrobial), benzophenone(sunscreen), glycerin (skin moisturizer), iodine (antimicrobial),vitamin A (skin healing), vitamin D and D2 (skin healing), aloe (skinhealing), octyl methoxycinnamate (sunscreen), anise oil, garlic oil,hydrocortisone (anti-inflammatory), salicylic acid (acne preparation),DEET (insect repellent), phenol-TEA complex (antimicrobial),clotrimazole (antifungal), and miconazole nitrate (antifungal).

[0058] Active ingredients that can be used in the topical compositionaccording to the invention include natural and synthetic drugs.Exemplary drugs that can be used for topical applications include thoselisted in U.S. Pharmacopeia and National Formulary, The United StatesPharmacopeial Convention, Inc., Rockville, Md. and Physician's DeskReference, Medical Economics Co., Inc., Oradell, N.J.

[0059] Surfactants can be incorporated into the topical composition toprovide controlled release of active ingredient or other component inthe topical composition. It is expected that the amount of surfactantand the type of surfactant can be adjusted to increase or decrease therelease rate. In the case where an active ingredient or other componentdesired to be released is relatively more hydrophobic, it is expectedthat by increasing the surfactant concentration, an equilibrium shiftfavors the aqueous phase and promotes a faster release of theingredient.

[0060] Surfactants that can be incorporated into the topical compositionaccording to the invention include nonionic surfactants, cationicsurfactants, anionic surfactants, and amphoteric surfactants, andmixtures thereof. It may be desirable to use surfactants when they havea tendency to increase the emulsion stability and/or to promote therelease of active ingredients. That is, surfactants can be used toincrease the water solubility of the polymers of the topical compositionand/or the surfactants can be used to decrease the binding of the activeingredients to the polymers of the topical composition.

[0061] Nonionic surfactants that can be used according to the inventioninclude ethoxylated, propoxylated, ethoxylated-propoxylated surfactants,and mixtures thereof. An exemplary nonionic surfactant that can be useaccording to the invention includes nonylphenol ethoxylate having nineethylene oxide groups and is available under the name Nonoxynol-9. Whennonylphenol ethoxylate is used according to the invention, it ispreferably provided in an amount of up to 5 wt. %, and can be providedat a concentration of between about 0.5 wt. % and about 5 wt. %; and ata concentration of between about 0.6 wt. % and about 1 wt. %. Asdiscussed previously, the amount of the surfactant can be adjusted toprovide desired emulsion stability and to effect the rate of release ofactive ingredient.

[0062] The use of surfactants for releasing active ingredients from thetopical composition is believed to be most useful with activeingredients that can be characterized as hydrophobic.

[0063] Anionic surfactants that can be used according to the inventionincludes salts of carboxylic (soaps) and sulfonate salts (detergents).Cationic surfactants that can be used according to the invention includeamides such as cocoamide. One concern with the use of anionicsurfactants, cationic surfactants, and amphoteric surfactants relates tothe potential destabilization of a emulsions as a result of the presenceof salts. Accordingly, it may be desirable to use anionic surfactants,cationic surfactants, and amphoteric surfactants at sufficiently lowlevels to reduce this destabilizing effect. It is expected that thesesurfactants will be used at lower levels than nonionic surfactants. Inaddition, the positive charge of the cationic surfactants and theamphoteric surfactants can have an affect of forming insoluablecomplexes with portions of the hydrophilic polymer composition.

[0064] When surfactants are used according to the invention, it isgenerally desirable to use the surfactant or mixture of surfactants inan amount that provides a desired level of emulsion stability andprovides a desired rate of release of active ingredients. It is expectedthat in most applications, the surfactant or mixture of surfactants willbe provided at a concentration of up to about 5 wt. %, and can beprovided in a range of 0.5 wt. % and 5 wt. %, and within a narrowerrange of about 0.6 wt. % and about 1 wt. %.

[0065] Although the topical composition has been described as acomposition that includes additional components, it should be understoodthat the topical composition can be used as a replacement for chemicalsor additives used in presently available topical compositions that areon the market. That is, certain ingredients of existing topicalcompositions can be replaced by the topical composition of theinvention. For example, may commercially available topical compositionsinclude several chemicals such as solvents or surfactants that are usedto hold active ingredients in the composition. The topical compositionof the invention can be used to hold or solubilize active ingredientswithout the use of the solvents or other components required by certaincommercially available topical compositions.

[0066] The topical composition use solution according to the inventioncan be provided in numerous applications. The composition can beprovided as a skin care product which is often used to administervitamins, aloe, herbs, and drugs to skin tissue. Exemplary vitamins thatare often delivered include vitamin A, vitamin E, and retinoic acid.Additionally, essential fatty acids such as borage oil and herbs such asaloe vera and evening primrose can be incorporated into the composition.

[0067] The topical composition can be used as a cosmetic composition.Exemplary cosmetic compositions according to the invention include lipcare products such as lipstick and lip gloss, eye care products, skincare products, fragrances, botanicals, oils, herbs, baby products, bathproducts, soaps, pigments, scents, alcohols, flavors, aloe, glycerin,powders, nail polish, and foundation.

[0068] The topical composition can be used as a barrier composition toprovide a barrier layer between skin tissue and the externalenvironment.

[0069] The composition according to the invention can be provided asover the counter products or prescription products. Exemplary over thecounter products include sunscreens, sun blocks, insect repellants,wound care products, bum care products, sunless tanning products,antifungal products, antibacterial products, antiviral products, acneprevention products, bath products, vitamins, minerals, deodorants, andanti-perspirants. The over the counter products can include drugs and/orpharmaceuticals. Prescription products can include peptides, metals,and/or drugs for skin disorders.

[0070] The composition according to the invention can be used as a haircare product, an animal care products, and a home care product.Exemplary hair care products according to the invention includeshampoos, conditioners, mousses, stylers, finishers, dyes, and hairsprays. Exemplary animal care products include soaps, hair shampoo, hairconditioners, flea and tick baths, and prescription drugs for skindiseases. Exemplary home care products include towelettes,disinfectants, soaps, and cleaners.

[0071] The composition according to the invention can be used to providean autocare product. Exemplary autocare products according to theinvention include fabrics, leathers, vinyls, paints, metals, chromes,rubber, tires, and window treatments.

EXAMPLES

[0072] The following examples were carried out in order to demonstratecertain teachings of the invention. It should be understood that theinvention is not limited to the examples of this application.

Example 1

[0073] Polyacrylic acid having less than 1% cross linking with a weightaverage molecular weight of between 400,000 and 500,000 and maleicacid/methylvinylether copolymer (MMVE) with a weight average molecularweight of 1,980,000 were used. For simplicity and ease of handling dueto lower solution viscosities, the majority of work was performed usingMMVE. The acidic polymers were easier to study by simple pH titrationsof free —COOH groups. When increasing concentrations of PVPE up to 10%were mixed with MMVE or PA under anhydrous conditions at temperatures of75° C. to 125° C., translucent, amber, waxy solids or liquids of highviscosity resulted. When heated in water to 65° C. and polymerconcentrations of 10-15% suspensions were obtained that could then betitrated with normal KOH. Results are shown in FIG. 1. Mixtures of MMVEand PVPH prepared in the same way gave the results shown in FIG. 2.

[0074]FIGS. 1 and 2 show MMVE without any added PVPE or PVPH has only50% of the —COOH groups titratable by KOH. Many Organic Chemistrytextbooks use the following structure to describe the hydrogen bondinginteractions of carboxylic acids.

[0075] For low formula weight carboxylic acids, the hydrogen bondinginteractions are considered weak ones in the area of 5 kcal/mole. Withpolymers having hundreds of —COOH groups per molecule and the addedcomplexity of inter-chain as well as intra-chain interactions, thesetypes of structures are likely quite stable and would require largeenergy input to disrupt them. Steric factors likely contributeadditional stabilizing factors.

[0076]FIGS. 1 and 2 also show that MMVE hydrogen bond structure isextensively disrupted by the addition of as little as 1% PVPE or PVPH.Adding more PVPE or PVPH results in the disappearance of —COOH groups.As seen in FIG. 3, the disappearance of —COOH groups is linear toslightly sinusoidal between 2 and 10% PVPE or PVPH.

[0077]FIG. 4 shows the effects on MMVE titration curves with theaddition of 20-50% PVPE or PVPH. The intention here is to maximize skinbinding (hydrophobic character) without extensive loss of watersolubility (hydrophilic character).

[0078] In the legend to FIG. 4 “HP” refers to “Hydrophobic Polymers” asthe data applies to PVPE and PVPH equally. FIG. 4 shows that while the“pKa” of MMVE changes slightly from 5 to 5.36, the mEqs. of Normal KOHrequired to reach the pKa is reduced by 75%, meaning that the number oftitratable —COOH groups also has been reduced and the Equivalent Weightof MMVE has increased. Clearly there is an interaction between the —COOHgroups of MMVE and PVPE and/or PVPH. It is difficult to perceive thisinteraction occurring between the C₁₆ and/or C₂₀ aliphatic side-chainsof PVPH and PVPE. We believe the pyrrolidone ring shown below isresponsible for this interaction.

[0079] This is the structure of N-methylpyrrolidone, which has the samecovalent structure as the pyrrolidone rings in PVPE and PVPH. Thepyrrolidone ring is chemically very stable, yet it has a carbonyl oxygenthat is electronegative and the amide nitrogen has a free pair ofelectrons, which can participate in resonance.

[0080] We believe the following structure explains the simplest form ofa non-covalent complex between PA or MMVE and PVPE and/or PVPH.

[0081] R₂═C₁₆H₃₃ or C₂₀H₄₁

[0082] R₁═[C₅H₁₁O₅]_(n) or [C₃H₆O₂]_(n)

[0083] R₅═[C₂₂H₄₁NO]_(n)

[0084] We realize that this complex as presented here is a simplisticform and may not exist at all primarily from steric considerations. Thecomplex may not involve adjacent —COOH groups or pyrrolidone rings. Theactual complex most likely involves intra-chain and inter-chaininteractions, resulting in a three dimensional structure far too complexto present.

Example 2

[0085] Another tool for studying polymers is viscosity. We hoped tolearn more information about the complexes by looking at viscositymeasurements at variable concentrations of PVPE and PVPH and also as afunction of temperature. FIG. 5 shows the results of these studies at apolymer concentration of 100 mg/ml. in water, and PVPE or PVPHconcentrations of 0 to 10% at a pH of 8.0, and over the temperaturerange of 32° C. to 65° C.

[0086] The surfaces of these plots are remarkably similar with a fewexceptions. At 2%, PVPE (blue surface) increases while PVPH (yellowsurface) decreases. This decrease in viscosity recurs between 6% and 10%concentrations, and persists up to 50° C. Attempts were made to extendthe study to lower total polymer concentrations (<100 mg/ml). Thisresulted in the complex dissociating at ˜10 mg/ml and completelycollapsing to starting materials at 5 mg/ml. PVPH was more prone to thisdissociation than PVPE.

[0087] Since complex formation appears essentially the same with eitherPVPH or PVPE, we decided to look at complexes formed with a mixture ofPVPH and PVPE. A molar ratio of 1:1 was chosen to begin the studies.Viscosity data for this mixture is shown in FIG. 6.

[0088] Comparison of FIG. 5 with FIG. 6 shows that the drop in viscosityfrom 6-10% concentration of PVPH+PVPE is greater than with PVPH alone,and the slope of the surface as a function of temperature is less withthe PVPH+PVPE mixture than with either PVPH or PVPE alone. Thisinteraction between PVPH and PVPE was unexpected.

[0089] It is believed that two types of phase separations occur with thepolymer complexes. The first is an upper phase of opaque, whitematerial. This is the result of insolubility of the complex. The secondis an upper layer of clear oily droplets or a waxy solid. This is theresult of complex decomposition.

Example 3

[0090] Since the polymer composition according to the invention isdesigned to bind to the skin with resistance to wash-off, we developed asimple and rapid, gravimetric method to mimic skin application of thepolymer system. This test utilizes hydrophilic nylon membranes normallyused for solvent filtration. It is expected that these membranes possessmixed hydrophilic and hydrophobic properties similar to skin.

[0091] The membranes are weighed to the nearest 0.1 mg. The pre-weighedmembranes are floated on a suspension of the test polymer solution andweighed to obtain the wet weight of sample applied. The membranes withtest polymer are dried at 32-35° C. (skin temperature) for 30 minutes,and a dry weight is obtained. The dried membranes may then be soaked inwater or a variety of solvents, re-dried and weighed a final time toyield the mg or % of polymer remaining on the membrane after treatment.It is expected that results on skin will be better.

[0092]FIG. 7 shows the results of our binding study with MMVE complexesof PVPH, PVPE and a 1:1 molar ratio of PVPH+PVPE.

[0093] Error bars indicate standard deviation of the mean. The expectedresults were that PVPE+PVPH>=PVPE>PVPH, reasoning that the C₂₀ sidechain of PVPE should adhere better than the shorter C₁₆ side chain ofPVPH. However, the data clearly show that the complex of MMVE: PVPE ismuch more soluble in water than the complexes of MMVE: PVPH or MMVE:PVPH+PVPE. The high binding point at 10% PVPH is also tantalizing,however, complexes containing 10% hydrophobic polymer or less decomposeto two phases in water within 24 hours of preparation. The MMVE:PVPH+PVPE curve hints that a cooperative interaction between PVPH andPVPE may be beneficial, but at lower molar ratios than 1:1. Similarstudies were conducted with PVPH: PVPE ratios of 10:1 and 22:1. Thesedata are shown in FIG. 8.

[0094]FIG. 8 clearly shows the synergism between PVPE and PVPH. EitherPVPH: PVPE mixture 10:1 M (10%) or the 22:1 M (5%) result in 15-25%greater binding to the membranes than seen by either hydrophobic polymeralone or the 1:1 M ratio of the two. FIG. 8 also shows that a mixture of95% PVPH+5% PVPE and 50% MMVE-H₂O yields a product that 75% remainsbound to the membranes after two hours of immersion in water. Similarbinding data demonstrated the PA-PVPE+PVPH system was substantially thesame (data not shown). At this point we considered the acidichydrophilic and PVPE+PVPH system optimized.

[0095] Implied by the non-covalent structure is an equilibrium processfor complex formation. The reversible nature of the complex by dilutionalso implies an equilibrium complex. Calculation of the ratio ofpyrrolidone groups of PVPH+PVPE to —COOH groups of MMVE for theoptimized, hydrated complex described above gives a value of 2.29:1.Because of the nature of the proposed complex, this value seems low.Complicating the issue is the fact that the complexes form emulsions,implying the complexes are not truly in solution, but are merely asuspension of micelles. This line of reasoning leads to the conclusionthat the factors controlling the equilibrium (or rather equilibria,there are likely many) are not primarily involved with the aqueousphase. This conclusion accounts for the high stability of what may bethought of as a labile complex.

[0096] The MMVE and PA polymer complexes described to this point requirethe neutralization of —COOH groups for water solubility. Thisnecessarily limits the useful pH range to 6-9 for formulation. It isexpected that similar complexes should also form with hydrophilicpolymers containing —OH groups instead of—COOH groups.

[0097] There are thousands of naturally occurring and man-made polymerswith abundant —OH groups. Among these are starch, cellulose, derivativesof starch, derivatives of cellulose, carboxymethyl cellulose, polyvinylalcohol, cyclodextrins, and dextrans. There is also the possibility thatpolyvinylpyrrolidone (Povidone) may also interact with PVPH+PVPE.

[0098] R₃═[C₆H₁₁O₆]_(n) or [C₂₈H₄₂O₂₅]_(n) or [C₂₅H₄₀N₄ ₄O₄]_(n)

[0099] R₄═OH

[0100] R₆═[C₂₆H₄₉NO]_(n)

[0101] All of the above compounds formed complexes with PVPE:PVPHmixtures under anhydrous conditions at temperatures between 80-110° C.The complexes were clear to translucent amber solids or high viscosityliquids. Hydration of these complexes to a total of 40-46% water at 65°C., produced hard, white to off-white, granular or waxy solids. Furtherdilution to working solutions of 10-15% polymer required the addition of0.5-10% surfactant (most often 9 to 10 mole nonylphenolethoxylates) toachieve stable emulsions.

[0102] In an attempt to overcome the difficulty of forming stable,aqueous emulsions, we dissolved the hydrophilic polymers in water atconcentrations of 11-17%, depending on the polymer's solubility thenadded PVPE:PVPH mixtures to final concentrations of 46-51% and heated to80-95° C. These reactions produced materials indistinguishable from theproducts formed under anhydrous conditions and hydrated post-synthesis.

[0103] As the —OH group polymers offer no easily analyzable groups as wehad with MMVE and PA polymers above, we began looking at binding data.The results for starch are shown in FIG. 9.

[0104] Unlike the MMVE polymer complex, 5 or 10% PVPE showed very littledifference in binding. Binding appears maximized at 10-20% PVPH+5 or 10%PVPE. However, significant decomposition (see Note above) of the complexoccurred at 10 and 20% PVPH+5 or 10% PVPE. The lowest stableconcentration was 30% PVPH+PVPE at all levels of PVPE, and the moststable aqueous emulsion paradoxically was at 40% PVPH+54% PVPE (1:1 M).

[0105] Results with polymer complexes utilizing polyvinylalcohol (PVOH)as the hydrophilic portion are shown in FIG. 10.

[0106] Carboxymethylcellulose (CMC), like PA mentioned above, iscommercially used as a viscosity builder for aqueous solutions. A 1%solution of CMC has a viscosity of ˜2,000 Csts/s. A 1% solution of PA atneutral pH has a viscosity of >4,000 Csts/s. At acidic pH, a 1% solutionof PA has a viscosity of ˜250 Csts/s. Neutralization of the —COOH groupson PA causes the increase in viscosity. CMC requires no suchneutralization as the —COOH groups are tied up as methyl esters.

[0107] Complex formation of CMC and PA with PVPH+PVPE mixtures givesdrastically different results. Complexes of PA under anhydrousconditions at 90 to 125° C. and subsequent hydration to a 40% watercontent, yields solutions or gels of extremely high viscosity, as if the—COOH groups have been neutralized, or are unavailable for titration asseen with MMVE. Subsequent dilution of these gels to 0.68% PA content,results in solutions of ˜5500 Csts/s. This is a considerable increase inviscosity over PA alone.

[0108] Complex formation with CMC under similar conditions results in asubstantial decrease in solution viscosity. PVPH+PVPE content in excessof 30% and dilution to a 1% concentration of CMC gives a solutionviscosity of ˜800 Csts/s.

[0109] Although the complexes formed with CMC and PA are believed to besimilar as shown in FIGS. 11 and 17, the results of the complexformation have drastically different effects on CMC and PA ability toincrease solution viscosity.

[0110] Results of the membrane binding studies with the CMC PVPH+PVPEcomplexes are shown in FIG. 11.

[0111]FIG. 11 shows that the CMC-PVPH+54% PVPE yields a higher degree ofbinding at all concentrations of PVPH+PVPE. At 40% PVPE+PVPH the 10%PVPE mixture is equivalent to the 54% PVPE mixture.

[0112] Cyclodextrins offer an interesting opportunity. Cyclodextrins areused as encapsulants in the food, cosmetic and pharmaceutical industry.They are cyclic oligosaccharides having 5 to 8 sugar residues withcavities in their centers. These cavities accommodate a wide variety of“guest” molecules that form stable complexes. The “guest” molecules maythen be released under controlled conditions. Formation of guestcomplexes can also stabilize molecules that are volatile or decompose inwater. A preferred cyclodextrin that can be used according to theinvention is β-cyclodextrin having seven glucose residues and has acentral cavity 6.5 Å in diameter and a formula weight of 1135. Arepresentation of this material is provided below.

[0113] Each glucose residue has 3 —OH groups (similar to Starch and CMC)that offer an opportunity for complex formation with PVPH+PVPE. It isdesirable to produce a polymer complex that is capable of encapsulatinga variety of active agents that will also bind tightly to hydrophobicsubstrates such as skin. Cyclodextrins are too water soluble to bind tothe skin for any appreciable time, particularly if the skin issubsequently exposed to water.

[0114] Most of the complexes with PVPH+PVPE shown in FIG. 12 lack anyappreciable solubility in water, a property that has been characteristicof all other polymer complexes. The notable exceptions are 10 and 20%PVPH+54% PVPE, which are completely soluble in water (pyrrolidone:—OHratios of 0.4 and 0.8 respectively). Since the cavity in theβ-cyclodextrin is known to be hydrophobic, and the water solubility ofthe guest effects the water solubility of the cyclodextrin complex, itis possible that PVPH and/or PVPE have occupied the cavity as a Guestmolecule. In addition, β-cyclodextrin is a relatively small moleculewith all of its —OH groups lying on the outside of the molecule. If allof the —OH groups formed complexes with pyrrolidone groups, none wouldbe available to promote water solubility. All of the complexes shown inFIG. 12, with the exceptions noted above, are soluble in nonpolarsolvents. This accounts for the >90% binding of the majority ofcomplexes in FIG. 12.

[0115] Closely related are the dextrans. Dextran is an oligosaccharideof glucose residues held together with α-1,6 glycosidic linkages muchlike starch. Dextrans lack the α-1,4 glycosidic linkages seen inamylopectin. Each glucose residue contains 3-OH groups to complex withPVPH+PVPE. Dextrans are used commercially as fillers, thickeners andwetting agents. A preferred dextran according to the invention isDextran-70 having a weight average molecular weight of 70,000 and arange of 60-90,000 (Low Fraction).

[0116] Dextran-70 is extremely soluble in water. It was anticipated thathigh levels of PVPH+PVPE would be required to achieve the waterresistant binding we desired. This was not the case as seen in FIG. 13.Binding rose sharply from 3% for the Dextran alone to nearly 80% withthe addition of 10% PVPH++PVPE. Binding remained nearly constant overthe range of PVPH+PVPE concentrations. All of the complexes formedstable emulsions.

[0117] Polyvinylpyrrolidone (PVP) forms sticky, yellow complexes withboth PVPH+PVPE mixtures and hydrophilic polymers. Although quite watersoluble itself, most of the complexes formed with PVP are highlyinsoluble in water. The complex formed between MMVE and PVP is a hard,transparent solid. This complex is soluble in water at a pH of 4.0 orhigher. FIG. 14 shows the titration curve for MMVE/PVP produced atfunctional group parity ratio of 0.9 —COOH/pyrrolidone.

[0118] When FIG. 14 is compared to the native MMVE data presented inFIG. 4, calculation of the Equivalent Weight of MMVE is 168, which isnearly twice the expected value of 87, based on the composition of MMVE.This calculation indicates ˜51% of the —COOH groups on MMVE are notavailable for titration. Calculation of the Equivalent Weight of theMMVE/PVP complex in FIG. 14, gives a value of 448, indicating ˜19% ofthe —COOH are available for titration. Since PVP has no aliphatic sidechains, the —COOH groups of MMVE must be tied up in a complex with thepyrrolidone rings as proposed in FIG. 11.

[0119] PVP is unique in our polymer complex system in that it can besubstituted for either the hydrophobic polymers or the hydrophilicpolymers and yet forms the same types of complexes. Complexes withPVPH+PVPE are soluble only in nonpolar solvents.

[0120] The PVP-PVPH+PVPE complex is soluble in ether-alcohol 75:25 orhexane. The PVP-CMC complex, formed in aqueous solution, retainsextremely high viscosity and limited water solubility, requiringhydration levels in excess of 85% to obtain working viscosities. PVP-CMCdries to a hard, transparent, brittle film. Once dried, the film isdifficult to hydrate.

[0121] The above specification, examples and data provide a completedescription of the manufacture and use of the composition of theinvention. Since many embodiments of the invention can be made withoutdeparting from the spirit and scope of the invention, the inventionresides in the claims hereinafter appended.

In the claims:
 1. A topical composition precursor comprising a result ofmelt processing: (a) hydrophobic polymer composition comprisingpoly(vinylpyrrolidone/alkylene) polymer, wherein the alkylene groupcontains at least about 10 carbon atoms; (b) hydrophilic polymercomposition comprising at least one of: (i) polyacrylic acid having aweight average molecular weight of at least about 50,000 and exhibitingless than 1% cross-linking; (ii) poly(maleic acid/methylvinylether)copolymer having a weight average molecular weight of at least about50,000; (iii) starch; (iv) derivatives of starch; (v) cellulose; (vi)derivatives of cellulose; (vii) carboxymethyl cellulose; (viii)polyvinyl alcohol; (ix) cyclodextrins; (x) dextrans; (xi) mixturesthereof, and (c) the topical composition precursor contains less thanabout 1 wt. % water.
 2. A topical composition precursor according toclaim 1, wherein the hydrophobic polymer composition comprises at leastdifferent poly(vinylpyrrolidone/alkylene) polymers, wherein the alkylenegroup of each polymer contains at least about 10 carbon atoms.
 3. Atopical composition precursor according to claim 2, wherein the at leasttwo different poly(vinylpyrrolidone/alkylene) polymers comprises a firstpoly(vinylpyrrolidone/alkylene) polymer and a secondpoly(vinylpyrrolidone/alkylene) polymer, wherein the firstpoly(vinylpyrrolidone/alkylene) polymer is provided at a concentrationof between about 5 wt. % and about 54 wt. %, based on the weight of thehydrophobic polymer composition.
 4. A topical composition precursoraccording to claim 1, wherein the hydrophilic polymer compositioncomprises polyacrylic acid having a weight average molecular weight ofbetween about 50,000 and about 4,000,000.
 5. A topical compositionprecursor according to claim 1, wherein the poly(maleicacid/methylvinylether) copolymer has a weight average molecular weightof between about 50,000 and 4,000,000.
 6. A topical compositionprecursor according to claim 1, wherein thepoly(vinylpyrrolidone/alkylene) polymer comprisespoly(vinylpyrrolidone/1-eicosene).
 7. A topical composition precursoraccording to claim 1, wherein the poly(vinylpyrrolidone/alkylene)polymer comprises poly(vinypyrrolidone/hexadecene).
 8. A topicalcomposition precursor according to claim 1, where the functional groupparity of the hydrophobic polymer composition to the hydrophilic polymercomposition is provided at a ratio of between about 1:1 and about 5:1.9. A topical composition precursor according to claim 1, wherein thefunctional group parity of the hydrophobic polymer composition to thehydrophilic polymer composition is provided at a ratio of between about1.5:1 and about 3:1.
 10. A topical composition precursor according toclaim 1, wherein the hydrophobic polymer composition is provided at aconcentration of between about 72 wt. % and about 98 wt. %, and thehydrophilic polymer composition is provided at a concentration ofbetween about 2 wt. % and about 25 wt. %, based on the weight of thetopical composition precursor.
 11. A topical composition comprising aresult of melt processing: (a) a result of melt processing: (i)hydrophobic polymer composition comprising repeatingpyrrolidone/alkylene groups, wherein the alkylene groups contain atleast 10 carbon atoms; and (ii) hydrophilic polymer compositioncomprising repeating carboxylic groups and/or repeating hydroxyl groups;and (iii) wherein the ratio of repeating pyrrolidone/alkylene groups torepeating carboxylic groups and/or repeating hydroxyl groups is providedat between about 1:1 and about 5:1 ; and (b) at least about 30 wt. %water.
 12. A topical composition according to claim 11, wherein thecomposition comprises between about 30 wt. % and about 45 wt. % water.13. A topical composition according to claim 11, wherein the compositioncomprises between about 3 wt. % and about 10 wt. % of the hydrophilicpolymer composition and between about 30 wt. % and about 50 wt. % of thehydrophobic polymer composition.
 14. A topical composition according toclaim 11, wherein the topical composition comprises between about 70 wt.% and about 96 wt. % water.
 15. A topical composition according to claim11, wherein the topical composition comprises at least one ofantimicrobial agents, antifungal agents, anti-inflammatory agents,anti-viral agents, sunscreens, vitamins, α-hydroxy acids, drugs,surfactants, dyes, fragrances and pigments.
 16. A topical compositionaccording to claim 11, wherein the hydrophobic polymer compositioncomprises a mixture of at least two differentpoly(vinylpyrrolidone/alkylene) polymers, wherein the alkylene group ofeach polymer contains at least about 10 carbon atoms.
 17. A topicalcomposition according to claim 11, wherein the hydrophilic polymercomposition comprises at least one of: (a) polyacrylic acid having aweight average molecular weight of at least about 50,000 and exhibitingless than 1% cross-linking; (b) poly(maleic acid/methylvinylether)copolymer having a weight average molecular weight of at least about50,000; (c) starch; (d) derivatives of starch; (e) cellulose; (f)derivatives of cellulose; (g) carboxymethyl cellulose; (h) polyvinylalcohol; (i) cyclodextrins; (j) dextrans; and (k) mixtures thereof. 18.A topical composition according to claim 11, wherein the hydrophilicpolymer composition comprises polyacrylic acid having a weight averagemolecular weight of between about 50,000 and about 4,000,000 andexhibiting less than 1% cross-linking.
 19. A topical compositionaccording to claim 11, wherein the hydrophilic polymer compositioncomprises poly(maleic acid/methylvinylether) copolymer having a weightaverage molecular weight of between about 50,000 and about 4,000,000.20. A topical composition according to claim 11, wherein the compositionfurther comprises between about 0.5 wt. % and about 5 wt. % surfactant.21. A topical composition according to claim 20, wherein the surfactantcomprises at least one of an ethoxylated surfactant, a propoxylatedsurfactant, an ethoxylated-propoxylated surfactant, and a mixturethereof.
 22. A method for manufacturing a topical composition, themethod comprising steps of: (a) melt processing a mixture to provide atopical composition precursor, the mixture comprising: (i) hydrophobicpolymer composition comprising repeating pyrrolidone/alkylene groups,wherein the alkylene groups contain at least 10 carbon atoms; (ii)hydrophilic polymer composition comprising repeating carboxylic acidgroups and/or repeating hydroxyl groups; and (iii) less than about 1 wt.% water; and (b) diluting the topical composition precursor to provide awater concentration of at least about 30 wt. % based on the weight ofthe topical composition.
 23. A method according to claim 22, furthercomprising a step of: (a) adding at least one active ingredient to thetopical composition, the active ingredient comprising at least one ofantimicrobial agent, antifungal agent, anti-inflammatory agent,anti-viral agent, drugs, sunscreens, vitamins, α-hydroxy acids,surfactants, fragrances, pigments, and dyes.
 24. A method according toclaim 22, wherein the step of melt processing comprises mixing thehydrophobic polymer composition and the hydrophilic polymer compositionat a temperature of greater than 50° C.
 25. A method according to claim22, wherein the step of melt processing comprises mixing the hydrophobicpolymer composition and the hydrophilic polymer composition at atemperature of greater than 125° C.
 26. A method according to claim 22,farther comprising a step of: (a) diluting the topical compositionprecursor with water to provide a composition containing between about30 wt. % and about 45 wt. % water based on the weight of the topicalcomposition.
 27. A method according to claim 26, further comprising astep of: (a) further diluting the topical composition in a separate stepto provide a composition containing at least about 95 wt. % water basedon the weight of the topical composition.
 28. A method according toclaim 22, further comprising a step of: (a) adding surfactant to thetopical composition.
 29. A method according to claim 28, wherein thesurfactant comprises at least one of an ethoxylated surfactant, apropoxylated surfactant, an ethoxylated-propoxylated surfactant, and amixture thereof.
 30. A method for using a topical composition, themethod comprising a step of: (a) applying the topical composition toskin tissue, the topical composition comprising a result of meltprocessing, at a water concentration of less than about 1 wt. %; (i)hydrophobic polymer composition comprising repeatingpyrrolidone/alkylene groups, wherein the alkylene groups contain atleast 10 carbon atoms; and (ii) hydrophilic polymer compositioncomprising repeating carboxylic groups and/or repeating hydroxy groups;and (iii) wherein the ratio of repeating pyrrolidone/alkylene groups torepeating carboxylic groups and/or repeating hydroxyl groups is providedat between about 1:1 and about 5:1; and hydrating to a waterconcentration of at least about 30 wt. % water.